Pick

• The <pick> construct allows you to block and wait for a suitable message to arrive or for a time-out alarm to go off.

<pick createInstance="yes|no"? standard-attributes>
  standard-elements
  <onMessage partnerLink="ncname" portType="qname"
             operation="ncname" variable="ncname"?>+
    <correlations>?
       <correlation set="ncname" initiate="yes|no"?>+
    </correlations>
    activity
  </onMessage>
  <onAlarm (for="duration-expr" | until="deadline-expr")>*
    activity
  </onAlarm>
</pick>
                
<!-- for example -->
<pick>
  <onMessage partnerLink="buyer"
                portType="orderEntry"
                operation="inputLineItem"
                variable="lineItem">
        <!-- activity to add line item to order -->
  </onMessage>
  <onMessage partnerLink="buyer"
                portType="orderEntry"
                operation="orderComplete"
                variable="completionDetail">
        <!-- activity to perform order completion -->
   </onMessage>

   <!-- set an alarm to go after 3 days and 10 hours -->
   <onAlarm for="'P3DT10H'">
        <!-- handle timeout for order completion  -->
   </onAlarm>
</pick>